Should lactose intolerant individuals avoid all milk and dairy products?

Most people with lactose intolerance can consume a moderate amount of lactose at one time without experiencing symptoms.

Although lactose intolerance is prevalent among some populations, total elimination of dairy foods is unnecessary. The ability to tolerate lactose is not an “all or none” phenomenon. The majority of lactose intolerant individuals can consume a moderate amount of lactose at one time without experiencing symptoms, considering the following factors.

Quantity

Individuals who experience symptoms after consuming less than one glass of milk should consume smaller servings of milk more frequently. Lactose maldigesters need to determine their individual threshold for occurrence of symptoms and adjust their lactose intake accordingly (1).

Stomach emptying time 

Lactase is active in the duodenum (first part of the small intestine) and the ability to handle lactose loads is very closely related to the amount of lactose emptying from the stomach. Drinking milk with other food rather than alone delays stomach emptying time and thus allows the remaining active lactase more time to digest lactose.The severity of symptoms decreases when lactose is consumed as part of a meal (2).  Drinking milk at room temperature or warmer slows down the stomach emptying time and may be better tolerated than cold milk (1). Due to its higher fat content, whole milk empties from the stomach more slowly than low fat milk and thus is better tolerated. Also, chocolate milk may be preferable to unflavoured milk because its higher osmolality delays stomach emptying (3, 4).

Type of dairy food

In addition to the quantity of lactose, the type of dairy food consumed also influences symptoms of lactose intolerance (2). Most firm cheeses (e.g. cheddar, swiss, mozzarella) contain little, if any, lactose. During the manufacturing of cheese, most of the lactose is removed with the whey. Furthermore, during the aging process of cheese, any remaining lactose is converted to lactic acid and other products (4). Consuming these foods can be considered an effective management approach to lactose intolerance (5).

References

1. Savaiano D A.1994. Lactose intolerance: dietary management. In: Dairy Products in Human Health and Nutrition. M. Serrano Rios, A. Sastre, M.A. Perez Juez, A. Estrala, C. de Sebastian (eds.). Rotterdam, Netherlands: A.A. Balkema. pp. 401–405.
2. Martini M.C., D.A. Savaiano.1988. Reduced intolerance symptoms from lactose consumed during a meal. Am.J.Clin.Nutr. 47:57–60.
3. Lee C.M., C.M. Hardy. 1989. Cocoa feeding and human lactose intolerance. Am. J. Clin. Nutr. 49:840–844.
4. Scrimshaw N.S., E.B. Murray.1988. The acceptability of milk and milk products in populations with a high prevalence of lactose intolerance. Am. J. Clin. Nutr. 48 (suppl.): 1083–1159.
5. Suchy FJ, Brannon PM, Carpenter TO, Fernandez JR, Gilsanz V, Gould JB, Hall K, Hui SL, Lupton J, Mennella J, Miller NJ, Osganian SK, Sellmeyer DE, Wolf MA. NIH Consensus Development Conference Statement: Lactose Intolerance and Health. NIH Consens State Sci Statements. 2010 Feb 22-24; 27(2): 1-27.